The respiratory illness storm ravages on. And it’s only November. Here is where we are with the “triple threat.”
Cases of RSV continue to skyrocket. Data shows we are testing a lot, though, as test positivity rates are not as high as in 2021. This is likely attributed to increased knowledge, which is good news. In addition, there are hints that RSV is peaking. With RSV, antigen test positivity rates usually peak before PCR, and that’s what we are seeing now. Cases may soon follow.
Historically, the RSV season lasts 5 months. It will be interesting to see how the holidays impact RSV patterns, though. Typically RSV peaks in January, but because it has arrived so early, we are in new viral dynamic territory.
There’s no doubt that social networks will change next week due to Thanksgiving. For example, we will see family that we don’t typically see. This will open up new pathways for transmission, and RSV numbers may therefore continue to rise.
Flu is right behind RSV and coming in hot; it’s earlier and steeper than previous pandemic and non-pandemic years.
We certainly see regional variability of the flu. A number of states in the South and the Atlantic seaboard, for example, have the highest activity level color that CDC records—purple in the map below. (The first time CDC used a purple color was in Louisiana in 2019, when they added it to the scheme due to very high levels.) This is causing flu surveillance at Johns Hopkins, for example, to go off the charts as seen below.
(Source: Andrew Pekosz)
There is good news from the Southern Hemisphere among countries that just concluded their flu season. Chile, for example, found the flu vaccine is a good match for the current strain. They are reporting a 49% efficacy rate. But only 28% of Americans are vaccinated against the flu. This is almost 10 percentage points lower than pre-pandemic rates, which is frustrating.
Interestingly, for the first time during the pandemic, there are more than 300 subvariants circulating, and not one is dominating globally.
This isn’t stopping the virus from causing waves, though.
SARS-CoV-2 is currently creating two global hotspots: Western Pacific and Southeast Asia. In South Korea, for example, we see an increase in cases and hospitalizations due to the variant soup (lots of lines of color in the figure below are increasing, as opposed to just one or two lines of color that we’ve historically seen).
(Source: Moritz Gerstung)
Other areas across the globe are starting to tick upward, including admissions in South Africa and Western Europe. Similarly, these upticks are not due to one variant but rather a mix of Omicron subvariants, waning immunity, weather, and behavior change.
(Source: Jean Fisch)
The real headscratcher is that the U.S. wastewater continues to plateau, but given previous patterns, a wave should have started by now as BQ.1 accounts for more than 50% of cases. A lot of eyes are on the West, too, as a new Omicron subvariant—BN.1— is growing.
Purple= Midwest; Pink= South; Orange=Northeast; Green= West. (Source: Biobot Analytics)
Given trends in Europe, it is still very likely that the U.S. will have a COVID-19 wave.
But, overall, this could be a good sign that we finally have an immunity wall that is challenging the movement of COVID-19, regardless of labs showing subvariants can partially escape immunity. We need to hold off on sweeping conclusions—like whether this pandemic is over— until this winter plays out.
The convergence of these diseases has three important implications:
- Impact on hospital systems. The hospitals, and in particular pediatric hospitals and emergency departments, are hanging. by. a. thread. Every pre-pandemic winter, pediatric hospitals were overwhelmed. This year the unique combination of circumstances is creating terrible strain, which has many implications, including the quality of care for everyone. We need to fix this on a systematic level.
- Risk of co-infections. Someone can be infected with two viruses at the same time. In fact, the first death from RSV and flu co-infection was reported in a child under 5 years old in California.
- Lessons not learned? I had hoped we would have applied lessons from COVID-19 to other diseases, like masking, staying home while sick, and getting vaccinated. Unfortunately, it doesn’t seem like this is happening. After 2.5 years of a pandemic, the public (and leadership) is just in a different state of morale, and the willingness to take preventative steps seems to be lower.
“Normal” viruses are continuing to show their muscle, and the seasonal virus repertoire now includes COVID-19. We are very concerned going into winter, as this situation is already applying massive pressure to hospital systems. Time will tell how the next few months play out.